Note: The formulas for
Hyperfocal Distance
above are very close approximations when the Camera-Subject Distance (between the front nodal-plane of the lens-system and the plane-of-focus) is significantly larger than the (actual) Focal Length multiplied by Zoom Factor. This is true in all but the very closest-up of of shooting conditions - so they can be considered to be accurate
.
.

Calculating the
Depth of Field
from the
Hyperfocal Distance

Units of either Meters or Feet can be used (as long as the same units are used when entering
HFD
and
D
).
HFD
is the
Hyperfocal Distance
(calculated from the above formulas).
D
is the Camera-Subject Distance (between the front nodal-plane of the lens-system and the plane-of-focus).

An approximation valid (with not more than 11% error) when
D
is equal to or less than 1/3 of
HFD

Depth of Field [DOF] ~ ( 2 ) x ( D^(2) ) / ( HFD )

A precise formula valid when
D
has a value less than the
HFD
(
undefined
when
D
=>
the
HFD
):